How Lasers May Have Revealed a Legendary Lost City of Gold

One year ago, a team of researchers traveled deep into the Honduran rainforest in search of Ciudad Blanca, the legendary lost city of treasures. Yesterday, they revealed images—uncovered by lasers—of structures that they believe to be the White City itself. The legend of the White City has captured explorers' imaginations for centuries; Hernán Cortés detailed his interest in the purportedly gold-laden metropolis as far back as 1526. But the Mosquitia region where it was rumoured to exist is densely packed with rainforest, and the conquistadors never penetrated deep enough to claim their prize.

Modern archaeologists have been just as stymied. Mosquitia has been the focus of a half dozen intensive explorations in the last century alone, some of which have yielded signs of some ruins and mounds. No one, though, despite their best efforts, had found anything close to a full city structure.

The team of researchers from the University of Houston, though, had something none of those expeditions did. They had lasers.

Major Laser

The National Center for Airborne Laser Mapping does just what you would think; uses highly advanced lasers to see things the human eye can't. Specifically, in this case, the team—led by a Los Angeles-based filmmaker—used a Lidar system to penetrate the thick foliage of Mosquitia and discover the treasures that lay beneath.

Lidar itself isn't particularly new. Developed in the 1960s, it was originally used to measure cloud densities, but comes in handy today for everything from mapping the Amazon rainforest to hunting down modern-day pirates. In this implementation, the system spits out laser pulses and measures how they're reflected off vegetation and the ground, to map the surface hidden beneath the forest's canopy.

By stripping away layers of reflections the researchers were able to remove detail from the canopy and reveal the ground beneath, shown on the right in the image above. Yesterday, the researchers revealed these images for the first time, at the American Geophysical Union Meeting of the Americas in Cancun.

The White Cities?

After others had spent centuries trying to unearth a single city of gold, the NCALM exploration made a surprising find: not one city, but two.

It might hard for the untrained eye to see, but the Lidar images revealed regularly spaced mounds—and a few other linear features—that possibly make up two distinct city centers. Either of which could very well be the legendary Ciudad Blanca.

We should know soon enough. The team is now closely studying the data to work out which sections contain the most promising features. Once they have, they'll deploy archaeologists to investigate the site further.

What will they find? Maybe rubble. Maybe gold. Maybe thousands of inexplicable golden orbs. The possibilities are endless when you uncover a legend right here in real life. [Nature]